I would go with a crested gecko! They stay small-ish, are handlable, dont require lights or heating. Only need to feed them a powder mixed with water and the occasional crickets and mist them everyday. That and babies go for about $30! I have mine in a 12x12x18 exo terra and its gunna last her awhile. Just make sure she has a hide on the bottom and thick plants and vines all around the tank. They are easy to breed too only downside is 2 eggs sometimes one per clutch. I love em!!!
X2 on the Crestie! They're great! I love my little one. They are gorgeous to boot!